Kranner Ilse, Grill Dieter
Inst. of Plant Physiology, Univ. Graz, Schubertstr. 51, A-8010 Graz, Austria.
Physiol Plant. 1993 Aug;88(4):557-562. doi: 10.1111/j.1399-3054.1993.tb01371.x.
The metabolism of low-molecular-weight thiols was investigated in seeds of Pisum sativum L. cv. Kleine Rheinländerin during imbibition in water for 14 h. The amount of oxidized glutathione (GSSG) decreased from 319 nmol (g dry weight) in dry seeds to 38 nmol (g dry weight) within the first 14 h of imbibition. The decrease may have been due to the reduction of GSSG to reduced glutathione (GSH), catalyzed by the enzyme glutathione reductase (GR; EC 1.6.4.2). The enzyme activity was high in dry seeds [25 nkat (g dry weight) ] and decreased to 20 nkat (g dry weight) within 14 h of imbibition. The activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) decreased from 100 nkat (g dry weight) in dry seeds to 67 nkat (g dry weight) after 14 h of imbibition. Within 14 h the amount of γ-glutamyl-cysteine (γ-GC) decreased from 135 to 38 nmol (g dry weight) , whereas the cysteine content rose from 81 nmol (g dry weight) in dry seeds to a maximum of 170 nmol (g dry weight) after 12 h of imbibition, which may be due to the degradation of γ-GC into cysteine.
在14小时的水浸吸胀过程中，对豌豆（Pisum sativum L. cv. Kleine Rheinländerin）种子中低分子量硫醇的代谢进行了研究。氧化型谷胱甘肽（GSSG）的量从干种子中的319 nmol（每克干重）在吸胀的前14小时内降至38 nmol（每克干重）。这种减少可能是由于谷胱甘肽还原酶（GR；EC 1.6.4.2）催化GSSG还原为还原型谷胱甘肽（GSH）。该酶活性在干种子中较高[25 nkat（每克干重）]，在吸胀14小时内降至20 nkat（每克干重）。葡萄糖-6-磷酸脱氢酶（EC 1.1.1.49）的活性从干种子中的100 nkat（每克干重）在吸胀14小时后降至67 nkat（每克干重）。在14小时内，γ-谷氨酰半胱氨酸（γ-GC）的量从135 nmol（每克干重）降至38 nmol（每克干重），而半胱氨酸含量从干种子中的81 nmol（每克干重）在吸胀12小时后升至最高170 nmol（每克干重），这可能是由于γ-GC降解为半胱氨酸所致。
